1. Technical Field
The present invention relates to a substrate for semiconductor devices.
2. Related Art
Conventionally, in the field of a substrate for semiconductor devices on which a semiconductor device is placed, it has been known to form a metal board below the substrate for semiconductor devices and solder it to a heat releasing board (refer to WO 2012/157584 and Japanese Patent Application Publication No. 2001-177053, for example).
However, for a conventional substrate for semiconductor devices, a heat stress generated in the substrate for semiconductor devices and the heat releasing board may cause a solder to overflow from an insulating substrate. The solder overflow from the insulating substrate reduces insulation properties.